we use a custom-made DITA framework in Oxygen 19 that is installed via an Add-On.

We know that we need to set 'Options | Preferences | DITA | DITA Open Toolkit' to "Custom" to make it work. With the first version of the Add-On, everything went fine.

But now, with the second version of our Add-On, we are unable to make that preference persistent by clicking on "OK" or "Apply", i.e. it always reverts back to the default of "Built-in DITA-OT 2.x" soon:

- The preference is kept when calling up the dialog again, but is lost as soon as any new document is created (even a simple "XML document").- The preference is always lost once Oxygen is restarted.

What can be the cause of this? Maybe errors in the framework that make Oxygen refuse using it?

Note that validation against the schema used by the framework now always fails, too, throwing the error "Invalid XML Schema: urn:..., unknown protocol: urn".

If you un-install the plugin, edit the Preferences->DITA page and set the custom DITA OT to point to some random folder, then restart Oxygen does the setting persist?If it does, then yes probably it's something caused by the add-on but without looking at the add-on and testing it on my side it's hard to tell...

If you can share the add-on with us you can use our support@oxygenxml.com email address.If you want to send a large zip you can do that using our tech support form:

Without the add-on, Oxygen behaved as it should. We found out that there was indeed a problem in the add-on. Now that we have obtained a new version of the add-on where that problem has been fixed, everything works fine and we are happy Oxygen users again!